Improve album cover loader, lyrics search and streaming support

- Improve album cover loader
- Add album cover loader result struct
- Move album cover thumbnail scaling to album cover loader
- Make init art manual look for album cover images in song directory
- Make album cover search work for songs outside of collection and
  streams
- Make album cover search work based on artist + title if album is not
  present
- Update art manual in playlist for local files, devices and CDDA
- Make lyrics search work for streams
- Add stream dialog to menu
- Remove dead code in InternetSearchModel
- Simplify code in InternetSearchView

src/internet/internetplaylistitem.cpp

@@ -46,9 +46,11 @@ InternetPlaylistItem::InternetPlaylistItem(InternetService *service, const Song
 }
 
 bool InternetPlaylistItem::InitFromQuery(const SqlRow &query) {
+
   metadata_.InitFromQuery(query, false, (Song::kColumns.count() + 1) * 1);
   InitMetadata();
   return true;
+
 }
 
 QVariant InternetPlaylistItem::DatabaseValue(DatabaseColumn column) const {
@@ -56,15 +58,26 @@ QVariant InternetPlaylistItem::DatabaseValue(DatabaseColumn column) const {
 }
 
 void InternetPlaylistItem::InitMetadata() {
+
   if (metadata_.title().isEmpty()) metadata_.set_title(metadata_.url().toString());
   if (metadata_.source() == Song::Source_Unknown) metadata_.set_source(Song::Source_Stream);
   if (metadata_.filetype() == Song::FileType_Unknown) metadata_.set_filetype(Song::FileType_Stream);
   metadata_.set_valid(true);
+
 }
 
 Song InternetPlaylistItem::Metadata() const {
+
   if (HasTemporaryMetadata()) return temp_metadata_;
   return metadata_;
+
 }
 
 QUrl InternetPlaylistItem::Url() const { return metadata_.url(); }
+
+void InternetPlaylistItem::SetArtManual(const QUrl &cover_url) {
+
+  metadata_.set_art_manual(cover_url);
+  temp_metadata_.set_art_manual(cover_url);
+
+}